Vibrating screen.



W. K. LIGGETY.

VIBRATING SCREEN.

APPLICAON FILED MYHV 192. RENEWE ULY 2.195. 1,171,058. Patented lieb. 8,1916.

4 SHEETS-SHEET l.

W. K. LIGGETT.

v VIBRATING SCREEN.

wPucAnoN man MAY8.1912. RENEwEo luLY 2.19m

1,171,058. Patented Feb.. 8,1916.

5% 4 SHEETS--SHEET 2 z 5% 5o 55 575.5 51 7 -4Z Il i5@ Wy K. LIGGET I.

mmm@ SCREEN,

APPLIQAUON FILED MAY 8, 9?2 KL'JE'WEU `Uv' 1,171,058.

Patented Feb. 8, 191V 4 SHEETS Y SHEET 3.

g 53. Q ily- W. K. UGGETT.

VBHATING SCREN.

nweuvw man MAYe.1912. Renfwfn :uw 2. m5.

1, 171 ,058. Patent-ed Feb. 1916.

4 SHEETSSHEET 4.

UNrrE-D STAT-Es PATENT, forero-E.

lWILLIAM K. LIGGETT, OF COLUMBUS, OHIO, ASSIGNOR TO THI) JEFFREY-MANU`FAC- 'DURING COMPANY, OF COLUMBUS, OHIO, A CORPORATION OF OHIO.

VIBRATIN'G SCREEN.

Specification of Letters Patent.

Patented Feb. 8, 1916.

Application led'May 8, 2912, Serial No. 695,853. Renewed `Iuly 2, 1915.. Serial No. t37,783.

To all 1o/Loiri. if: may] Conce-rn.'

lle. iiV known that l, finanza K. Lroon'rr, a. citif/.eu of the. United States, residing at Columbus, in the county out Franklin and State of Qhio, have invented `certain new and useful .improvements in 'Vibrating Screens, of which lthe following is a specifiaeeompanying drawing.

This invention relates'to improvements in screening nwehanismsl and particularly to thatrlass comprising those in which an inclined srreen cloth, along?r the upper edge of whieh is .ted the. material to be screened, is mechanically viorated thereby facilitatcation, referencebeing had therein Vto `the y ing the passage.through the screen of all material of a size smaller than the mesh ration of the screeningA apparatus Fig. 2V

is a` longitudinal vertier-al sectional View through the screening' apparatus. Fig. 3 is a perspectivevii-w showing a spreader frame lo'heused in the screening apparatus when m'ore. than one screen is used. Fig. l is a front elevation with parts broken away. Fig. 5 is a rear elevation. Fig. 6 is a fragmentary side elevation of the improved screen vibrating;r mechanism. Fig. 7 is a sectional view on the line. 7 7 of Fig. showing the screen vibrating cam. l"i S is a sectional view on vthe line 8-8 of Fig. 5 showing the screen supporting and rushioninpY device. Fig. 9 is a fragmentary longitudinal verlirfal sectional view showing in detail theI hopper and itsifeeding mechanism. Figs. l(! .'ll and 12 are diagrannnatie views of the screen vibrating mechanism in several diti'ererit positions.

Referring?r to the drawings, the, numeral l indicates in general the screen stretchers and their supports whieh. together with the vibratingr de-viee comprises the. screening mechanism proper. The screens are mounted within a casing provided with suitable doors for easy access to the interior, this casing;r being supported upon a. structural framework adapted to befsecured to a suitable foundation. The casing comprises verf,

tical side plates 2, the vfront 3,. 'with its swinging door 4, the inclined bott-om 5,

theupper back. (i and the inclined top 7 which is provided with two large hinged inspection doors 8, 8. An open section is provided in the bottom of the 'at ,9. through which .the various gradesof ma: terial after screening fall by `igjrfaaiity into the hopper-s or chutes located `below the' level of the apparatus. Tliewfrrmework 10 supports the easing upon its tondtion 10.

the casing and provided wit` 'paWl and shaft 15 is mounted in the front portion of r sci tinuous and passes E'through t extvjo holes 17 drilled diametrically throiighzthefshaft 15. A hand when 18 is-attjacnedlito the end of the shaft 15 by means of; Awhich-itA isV operated thereby raisingfor Vlowering the lower end of th'e screen, the` ratchet device holding it in any desired position.

The screen frame 11 is pryidedat lits lower end and along its sidesiwith opstanding fingers 19 which hold'the screen-stretchers in position and prevent "displacement during?r operation. Side piece s` 20 are secured te the sides of the frame andpreventmaterial from over-running the edges of the screen. v Y y l.

When more than two grades orv sizes ot' material are desired, it is possible with my 28 and' 29. W'hen the spreader is placedin the lower end of the trame, the lower screen stretcher 21 will abut against the ends of the stretcher and Vmaterialfallingthrough this screen willbe-divertcd by tlieapron 2G. The second screen stretcher -22 is placed upon the step 28 of the spreader and material falling through this screen, and failing 'to go through lthe screen held by the stretcher 2l, wi-ll be diverted between the two`aprons 2G a d 27. The upper screen stretcher 23 is pl.. ced upon the highest step 29 of the spreader and is supported at its lower end b Y the fingers 19 secured to the frame 11. llaterial falling through this screen and of a size too large to pass through e the' screen carriedv llygthestretcher 22,v is diverted'between the apron 27 attached to the spreader and the apron 30 attached to the lower corner of the frame 11.

NllVit-h this arrangement by which the lower ends of the screens are separated allowing the passage of material between them, the various grades are diverted. into the bins or chutes A, B, C and D. The aprons are made in two'thicknesses or folds so that they can straddle the upper edges 31 of the chutes or bins into which they guide the material.

Several figures in the drawings have shown three screen stretchers placed upon the screen supporting frame, but it is of course evident that a greater or less number of screening surfaces may be used, depending upon the number of grades into which it is desired to separate the material being screened.

The transverse rod 12 upon which the upper end of the screen frame 11 is mounted passes outward through openings in the sides 2 of the casing and is supported in blocks 32 which slide within vertically arranged guide brackets 33 attached to the upright casing supports 10. Verticallyarranged coil springs 34 are placed within the brackets 33 and bear against the upper and lewer sides of the blocks 32. This arrangement allows the upper end of the screen mechanism to receive a vertical floating or .spring cushioned motion, the tension of the springs being adjusted by set screws 35 gzassing through the ends of the brackets 33.

,i transverse shaft 36 is mounted in journals 37 upon the upper face off the casing and driven' by a pulley 38. Mounted upon this transverse sha t at each 'side of the casing are two eccentric-s 39 carrying eccentric straps 40. The cross section of fach eccentric and strap 1S arced as shown in Fig. 7 to prevent the strap from running oflr the sides of the eccentric, the inner surtace oi the strap 'being babbitiedl at 41. A hule is drilled through the upper eccentric etrap and a grease cup 42 tapped into the hole to provide lubrication for the eccentric.

Blocks 43 are placed upon the ends of the rod 12 and'vv are slidably mounted within two separable bumper bloc is 44. Connecting the bumper blocks and the eccentric strap arey two rods 45 which act pitmen and also' secure together the two halves ot the eccentric straps 40. The lower ends ot' the ro'ds or pitmen are threaded and pass through the bumper blocks 44. Nuts 4G are placed upon the threaded portion of the rods 45 above and below the two bumper blocks. Coil springs 47 surround the rods 45 and are placed 'between the two blocks, extendingr into recesses 48 in the inner faces of the bumper blocks. These springs separate the two bumpei` blocks and press them resiliently against the limiting nuts or stops 4G. of the'rod 12 so as to prevent the bumper blocks from becoming displaced and slipping over the-blocks '43 when the machine is in operation. 1

The rotation of the shaft 36 through the eccentric 39 causes the rapid reciprocation of the two pitmen 45. The pitmen in turn cause the bumper blocks to vibrate rapidly back and forth upon lines slightly inclined from the vertical. By adjusting the nuts 4G the bumper blocks may be spaced toward or away from the blocks 43 so that the bumper blocks will travel a shorter or a greater distance before coming in contact with the blocks 43. The tendency of the supporting springs 34 is to constantly hold the rod 12 at a central point. The recipro- `eating bumper blocks give the rod 12 a short up and down motion.

Considering the pitman at its lowest position, the upper bumper block will be in contact with the upper side of the block 43 having pressed it to its lowest limit. As the eccentric swings past the center, the pitman will be at its lowest limit as diagrammatically shown in Fig. 10.-" As the eccentric passes its center and carries-the pitman in an upward direction, the lower of the two coil springs 34 forces the rod upward Ito its central point indicated diagrammatically by Fig. 11. The next step in the cycle is the further upward movement of the pitman in which the upper bumper block draws away from the, block 43 and the lower bumper block is brought sharply up against and delivers a hammer blow to Vthe lower edge of the block 43, this latter position being illustrated diagrammatically in Fig., 12. On the downward throw 'of the' eccentric the reverse train of operations is performed., The shaft 36 revolving at considerable speed in;v thismanner delivers a succession of sharp hammer blows tothe upper end of the screen alternating from an upward to a downward direction.

By adjusting the nuts 46 outward or inward upon the rods 4:5, the spacing 0f the Collars 49 are secured upon the ends' bumper blocks will be varied thereby vary ing the distance through which they will travel before delivering their blows to the ends of the rod. This allows of a. wide variation in adjustment adapting the 1na chine to various degrees of vibration depending upon the quality of material being screened. By this adjustment it is evident that the nuts may be tightened down so that the bumper blocks will contact on both sides of the block 43 thereby reliminating the hammer blows and thus/'give the ends of the rod l2 the smooth/lip and down movement equal to the throw of the eccentric. (ln the other hand, the nuts may be run out upon the rods 45,/ the springs 47 forcing the bumper yblocks outward against the bolts to a point where. the distance between the inner faces of the bumper blocks and the bloeit 42.5 will almost equal the entire. throw ol' the eccentric. In this position tbe ends of the rod 12 will be barely moved, but will re ceive alternately upward and downward a light tapping communicating to the sei-een a gentle vibration adapted for the best screening of certain grades of material.

Mounted on the upper end of the easing is my improved hopper and feeding devire comprising the chute 5t) feeding into a trough 51 extending the entire width of the. casing and provided at its lower portion with an inclined plate of a flexible mai teria] such as sheet steel, and securely bolted along its rear edge to the casing. t`o-acting with this inclined plate or feeder bottom is a vertically slidable gate 53' positioned at thex front of theI hoppe' and adapted to be raised or lowered by hand wheels 54. An upturned lip is formed n the lower edge of the plate 52 and eoacts with the, gate 5? to prevent the material from flowing out through the hopper except when the plate 53 is vibrated. transverse angle piei-e it is riveted along the under side. of the iuclined plate 5:). and has attaehed to it downward and forward extending arms 5T. These.g arms rest upon or hear against pins or lugs 58 attached to the side pieces 2() of the sri-een' frame 11. The forward extending parts ofe the arms 57 arel curved in ares about the rod l2 as a center so that when the lower end of the screen frame is raised or lowered` the upper end swinging about the shaft l2. the lugs 58 will bear at all times the .same rela'- tion tothe arms. l`he vertiral ibration of the upper end ofthe sei-een frame is through the above described arrairfemeut transmitted through the arms 5T to tbe inclined ilexiblr plate 5;. this rapid vibration ausilio ma terial lo llow downward over the, plate iu .i steady stream. the amount depending' npou the elevation of the gate Sil. rl`he vibration ot4 this plate whirh is securely fasieiual to its rear edge to the easingis ot' a nature that --.=oot be obtained where the rear ulge of the` plate or hopper bottom is pivotally mounted. (hi the upward travel of the screen frame the hopper bottom, iustead of being swung upward as is the ease of the pivoted bottoms, is bent upward iu a sliglit are. this heilig found to greatly t'aeilitate the distribution of the material transverse the feeder' plate and give superior results.

The. mounting of th(` screen stretrhers in the manner described makes it possible to easily adapt the machine for a variety of sizes as tbe screen stretehers ma): easily bc taken out or additional ones put in depending upon the number of grades desired. This is accomplished by using the spreader or adapter shown in Vig, which separates thi-screening surfaresin suoli a manner that individual troughs or rbutes are provided for the spare intermrdiate the srrcening .surfaces without making any alteration in the apparatus itself.

The upper end of the screen is tapped 0r hammered alternately upward and downward in a vertical plane while the lower end of the screen is adjustably supported by flexible rables. This arrangement is found to give a lnost etlirient screening action in that the particlesl of material. instead ot taking long. jumps over the screening surY face, are caused to rapidly vibrate. up and down in more nearly vertieal lines giving greater etlieieluy for a given screening surface than is the ease where the partit-les take longer liumps. l-"urtberniore. the hammering aetion in a vertical plane rauses tbe sereen- T'ng surfare to Iiump away from tlu` material bn the downward throw and to be plirlily forced into eontaet with thil material on the. upward stroke.

vbat l elaim is: Y-

l. ln a sereeniug apparatusi the eombiuation with the frame. of the iin-lined screen. the ilevible suppoii for the lower end of the screen. and means for vibrating the up per end of the screen in a vertical plane by flows,delivered alternately in au upward 'iiid downward direction.

"2. ln a srreeniinrlP apparatus. the. rombinataon with the frame. ot' the iin-lined sereen, thevertiraltvadiustallesupport l'ortlielower end ofthe screen. and the means tiu' vibratV in; r the uppereud ofthe ,si-reen ina vertieal plane by hammer blows alternating in an upward and downward dirertion.

:L ln a sei-veiling apparatus. the rombin`ation with the frame. ol' the iurlined screen.

the tlexible support for the lower end of the screen. thi` floating support for the upper end ot' the srreen. and meansl for vibrating the upper end of the screen by means ot' hannner blows delivered alternately in opposite. direct ions.

4. ln a screening apparatus, thc eombina tion with the frame, of the inclined screen,

hinged or llO the vertically adjustable support for the lower end of the screen, the vertically floating support for the upper end of the srrcen, and the means for delivering hammer blows alternately in opposite directions to the upn per end ot the screen.

.3.' ln a screening apparatus, the combination with the inclined screen, ol the support for the lower end of the screen, the loating support for the upper end of the screen, and the means for delivering heur mer blows to the upper end of the screen in alternate directions.

6. In a screening apparatus, the inclined screen, the flexible support. for the lower end of the screen, the transverse rod ca rrying the upper end of the screen, the spring cushioned supports for the ends ot' the said rod, and means for delivering hammer blows to the said rod alternating from an upward lo a downward direction.

7. In a screeningr apparatus, the combination with a fame, of an inclined screen, a support for the lower end of the screen, the transverse rod carrying the upper cud of the screen, supports cushioning the transverse rod in both an upward and downward direction' attached to the :trame` and means for alternately hammering' the ends ot the rod in opposite directions.

8. In a screening apparatus, the combination with the frame, of the inclined screen, the zlexible support for the lower end of the screen, the transverse rod carrying the upper end of the screen, the springs supported inthe frame and adapted to cushion the ends of the rod in both vertical directions, and the eccentrically driven pitman co-acting with the ends of the rod to hammer the said rod alternately in an upward and downward direction.

9. In a. screening apparatus, the. combination with the frame, of the inclined screen. the flexible support for the lower end of the screen, the transverse rod carrying the upper end of the screen, the springs carried by the frame and adapted to cushion the ends of the rod in an upward and downward direction, and the eccentrically operated pitmen, the free ends of the said pitmen loosely embracing the ends of theA rod and thercbj,Y alternately hammering the ends of the rod in opposite directions.

10. In a screening apparatus, the comliiination with the frame, of the inclined screen, the flexible support for the lower end of the screen, the springs carried by tle frame to cushion the upper end of the screen in both vertical directions, and the reciprocating pitmen, the lower ends of the said pitmerr adapted to co-iirt with the upper end of the screen and alternately hammer it in an upward and downward direction.

il. In a screeningY sigaar-fares, the ronihination with the frar nl the inclined screen, a support for the lower end 0f the screen, the transverse rod supporting the upper end of the screen, the springs carried by the frame for supporting and cushioning the rod in both vertical directions, the reciprocating pitmen and the bumper blocks secured to the pi tmen and loosely surrounding the ends of the rod.

12. In a screening apparatus, the combination with the frame, of the inclined screen, the support for the lower end of the screen, the transverse rod'supporting the upper end of the screen, the reciprocating pinnen, and the bumper blocks secured to the pitmen, the said blocks loosely embracf ing the ends of the transverse rod.

13. In a screening apparatus, the combination with the trame, el the inclined screen, the support for the lower end of the screen, the transverse rod supporting the upper end of the screen, the springs secured to the frame and adapted to spring cushion the transverse rod in both vertical directions, the reciprocating pitmen, and the spring separated bumper blocks carried by the pitmen and embracing the ends of the rod, said blocks being adapted on recipro-L cation of the pitmen to hammer the ends of the rod alternately in opposite directions.

14. In a screening apparatus, the combination with the frame, of the inclined screen, the support for the lower end of the screen, the transverse rod secured to the upper end of the screen, the springs carried by the frame and adapted to support and cushion the ends of the rod in both vertical directions, the reciprocated pitmen, ther bumper blocks secured to the pitmen, the bumper blocks heilig provided with openings to embrace the ends of the rod, and means for varying` the size of the openings.

15. In a screening apparatus, the combination with the frame, of the inclined screen. the support for the lower end of the screen. the transverse rod supporting the upper end ot' the screen #the reciprocating pltmen, the blocks mounted on the ends j of the rod, and the bumper blocks secured,- to the ends of the pitmenand loosely eng 4 1 15 ing the said blocks on vthe ends ofthe r( 1V. In a screening,/apparatus, the ,conn bination with the frame. o? the inclined Screen, the Support ,fr lll? lUWQI.' QHd'Of the screen, the transverse rod supporting the upper end of the screen, the reciprocating pitmen, the blocks mounted on the ends of the rod and the bu ur blocks secured to the endslof the pitmenhe said bumper brocha being prfwided ith openings adapt- 12F ed to receive the blocks on the .mds of the rods, the said openings having greater dinufnsions longifudinzd of the pitmcn than the blocks on rin rod, substantikli); as and for the purpose set LlKfrth.

17. In a screening apparatus, the combination with thel frame, of the inclined screen, the support for the lower end of the screen, the transverse rod supporting the upper end of the screen, the reciprocating pitinen, tlie blocks mounted on the ends ot' the rod, llie bu'lnper blocks secured to the ends of the pitnien, the said blunper blocks being provided with openings adapted to receive the blocks on the ends of the rod, said openingA having greater dimensions longitudinal ot' the pitinen than the blocks on the rod, and means for varying the said longitudinal dimensions' ot' the openings in the bumper blocks, substantially as and for the purpose set forth.

1S. The combination in a screening apparatus, with a vibrated screen supporting frame, of the plurality of screen stretcliers, and the detachable spreader adapted to be placed within the screen supporting frame and separate the lower ends of the screen Istretcllers, substantially as and for the purpose set forth.

19. The coinbinatlon 1n a screening apparatus, with the vibrated screen supporting frame, of the plurality of screen stretchers, the spreader frame detachabl mounted within the vibrated frame andy adapted to support and separate the lower ends of the screen stretchers and the aprons attached to the said spreader frame and adapted to divert material separated by the said screens.

20. In a. screening apparatus, the combination uitli tbe vibrated screen supporting frame, ot tbc plurality of screen stretchers, the upstanding finger pieces extending from the sides of the said frame, and the spreader frame resting upon the lower end of the vibrated frame and secured from displacement by the upstanding fingers, said spreader frame adapted to separate the lower ends'of the screen stretchers placed within the vibrated frame.

In testimony whereof I ailix my Signature, in presence of two witnesses.

WILLIAM K. LIGGETT.

, Witnesses:

GUsTAv EILBERT, DUDLEY T. FISHER. 

